Unit 3 - Life on Earth Flashcards Preview

The variety of life forms in a particular area. The higher it is the better

Biodiversity

2

Organisms which produce their own food source

Producers

3

Organisms which require to eat other organisms to survive

Consumer

4

Organism which only eats plant material

Herbivore

5

Organism which eats both plant and animal matter

Omnivore

6

Organism which only eats animals

Carnivore

7

Define the word:

Species

Organisms that can reproduce to have fertile offspring

8

The number of one species of organism in a habitat

Population

9

All the different species in a habitat

Community

10

Define the word:

Ecosystem

All the living organisms and non-living components in a particular habitat

11

Define the word:

Niche

The role an organism plays within a community

12

Intraspecific competition occurs between ...

Members of the SAME species

13

Interspecific competition occurs between ...

Members of different species

14

Give an example of something organisms would compete for

Sunlight (plants)HabitatFoodMates

15

Why is intraspecific competition more intense than interspecific?

Organisms of the same species all require the exact same resources

16

Non-living factors that affect biodiversity.

Abtiotic factors

17

Examples of abiotic factors

TemperatureORLight intensityORpHOROxygen concentration

18

Examples of biotic factors

PredationORGrazingORFood availabilityORDisease

19

The place an organism lives

Habitat

20

A relationship between animals in which one hunts, kills and eats the other

Predation

21

A feeding relationship between two organisms in which one organism benefits and the host is harmed

Parasitism

22

Percentage of energy lost at each level of a food chain

90%

23

Percentage of the energy in food used for growth

10%

24

Ways in which energy is lost at each level in a food chain

HeatORMovementORUndigested food

25

A diagram with the width of each bar representing the number of organisms at that feeding level in a food chain

Pyramid of numbers

26

A diagram with the width of each bar representing the total mass of organisms at each stage of a food chain

Pyramid of biomass

27

A method for sampling ground living invertebrates in an area by placing concealed pits for them to fall into

Pitfall traps

28

A square placed on the ground before counting the plants inside

Quadrat

29

Ways to reduce sampling error with quadrats or pitfall traps

Place randomly

Take many samples

30

Reason for sampling several times with a quadrat

Increase reliability

31

Instruments used to measure abiotic factors

Light meterORMoisture meterORpH meterORThermometer

32

Helped to identify organisms

Biological keys

33

Their presence or absence indicate environmental quality/levels of pollution

Indicator species

34

Number of stages in photosynthesis

2

35

First stage of photosynthesis in which water is split

Photolysis

36

Molecule which traps light energy from the sun

Chlorophyll

37

Leaf organelle which contains chlorophyll and is the site of photosynthesis

Chloroplast

38

Energy rich molecule synthesised during the light reaction

ATP

39

Type of energy in ATP

Chemical energy

40

Required to synthesis ATP

ADP + Pi + energy

41

Produced when water is split

Hydrogen and Oxygen (and energy)

42

A by-product of water splitting that diffuses out of the leaf

Oxygen

43

Carries hydrogen from the first to the second stage

Hydrogen Acceptor

44

Second stage of photosynthesis where glucose is synthesised

Carbon fixation

45

Controls the series of photosynthesis reactions

Enzymes

46

Produced by water splitting and combines with carbon dioxide to produce glucose

Hydrogen

47

Molecules required to produce glucose

Hydrogen, Carbon dioxide and ATP

48

Product of photosynthesis that can be used in respiration or converted to other molecules

Glucose

49

Structural carbohydrate used to make cell walls

Cellulose

50

Storage carbohydrate in plants

Starch

51

Word equation for photosynthesis

Water + Carbon dioxide -----> Glucose + Oxygen

52

Term for an essential input in short supply that reduces the rate of photosynthesis

Limiting factor

53

Limiting factor on a cloudy day in summer

Light intensity

54

Limiting factor on a sunny day in winter

Temperature

55

Three factors that may limit the rate of photosynthesis

Light intensity & temperature & carbon dioxide concentration

56

Nitrate rich substances used by farmers to grow crops

Fertilisers

57

Chemicals use by farmers to eradicate insects and weeds

Pesticides

58

Process of fertilisers leaching into fresh water

Eutrophication

59

Define the process of eutrophication

1. Fertilisers wash into rivers and lakes2. Algal blooms grow and block out light3. Plants in water die and eaten by bacteria4. Bacteria use up available oxygen in water5. Animals may die due to lack of oxygen

60

Technique involving gene alteration to reduce fertilisers

Genetic modification

61

Term given to pesticides accumulating in food chains, causing increased toxicity

Bioaccumulation

62

Random changes to genetic material that are the only source of new alleles

Mutation

63

Environmental factors that increase the rate of mutation

RadiationORUV lightORX-raysORSome chemicals

64

An inherited characteristic that makes an organism well suited to survive in its environment

Adaptation

65

Biological term for a group of organisms that can interbreed and produce fertile offspring

Species

66

Biological term for an organism best adapted to its environment surviving and passing on its favourable alleles to its offspring

Natural Selection

67

Biological term for an organism best adapted to its environment surviving and passing on its favourable alleles to its offspring

Natural SelectionORSurvival of the fittest

68

Factors in the environment which make the survival of certainindividuals more likely than others

Selective pressures

69

The process by which a new species can arise as a result of the isolation of a part of a population in an environment with different selection pressures

Speciation

70

When part of a species is separated from the rest so that they cannot interbreed for a long period of time

Isolation

71

A reason for different alleles arising in two isolated sub-populations

Mutations

72

Biological term for the gradual change in the genetic make up of a population as a result of natural selection over many generations.

Evolution

73

What results when different selection pressures select fordifferent mutations in two isolated sub-populations over a long periodof time?